Gold ore can be mined at level 40 Mining providing 65 Mining experience. After a Gold rock is mined, it will take 60 seconds until it reappears.

Gold ore is the raw material used to smelt a gold bar. Smelting gold ore into a bar gives 22.5 Smithing experience, or 56.2 with the Goldsmith gauntlets equipped. Since smelting gold bars is an easy way to gain Smithing experience, gold ore is often sold at higher prices than the bars.

Spawn rates of pretty much everything in Old School will now be consistent throughout all worlds...[and] resources and monsters now spawn at a standardised rate throughout all worlds regardless of how many people are currently online.

”

— Mods Alfred, Ash, John C, Mat K, Reach, Ronan & Weath

That means gold spawns at a standardised spawn rate, which is one minute after it was last mined, no matter how many players are on a world. Whether it's zero or 2000 players in a single server, all ore across the game will respawn at the same rate.